Stop and listen to the people: an enhanced approach to cancer cluster investigations

Health Hazard Evaluations of occupational cancer cluster concerns: the USA, January 2001-December 2020

OBJECTIVES

To describe recent investigations of potential workplace cancer clusters.

METHODS

We identified Health Hazard Evaluations (HHEs) of cancer concerns during 2001-2020. We described information about industry, requestors, cancer characteristics, investigative procedures, and determinations about the presence of a cluster (ie, presence of excess cases, unusual case distribution or exposure).

RESULTS

Of 5754 HHEs, 174 included cancer concerns, comprising 1%-5% of HHEs per year. In 123 HHEs, the cancer cluster concerns involved different cancer primary sites. Investigation procedures varied but included record review (n=63, 36%) and site visits (n=22, 13%). Of 158 HHEs with a cluster determination by investigator(s), 151 (96%) were not considered cancer clusters. In seven HHEs, investigators found evidence of a cluster, but occupational exposure to a carcinogen was not identified.

CONCLUSIONS

The proportion of HHEs on workplace cancer cluster concerns remained steady over time; most did not meet the definition of a cluster or uncover an occupational cause. Public health practitioners can use this information to provide updated context when addressing workplace cancer cluster concerns and as motivation to refine investigative approaches. More broadly, this review highlights an opportunity to identify best practices on how to apply community cluster investigation methods to the workplace.

Investigating outbreaks of initially unknown aetiology in complex settings: findings and recommendations from 10 case studies

BACKGROUND

Outbreaks of unknown aetiology in complex settings pose challenges and there is little information about investigation methods. We reviewed investigations into such outbreaks to identify methods favouring or impeding identification of the cause.

METHODS

We used two approaches: reviewing scientific literature and soliciting key informants. Case studies were developed through interviews with people involved and triangulated with documents available from the time of the investigation.

RESULTS

Ten outbreaks in African or Asian countries within the period 2007-2017 were selected. The cause was identified in seven, of which two had an unclear mode of transmission, and in three, neither origin nor transmission mode was identified. Four events were caused by infectious agents and three by chemical poisoning. Despite differences in the outbreaks, similar obstacles were noted: incomplete or delayed description of patients, comorbidities confounding clinical pictures and case definitions wrongly attributed. Repeated rounds of data collection and laboratory investigations were common and there was limited capacity to ship samples.

DISCUSSION

It was not possible to define activities that led to prompt identification of the cause in the case studies selected. Based on the observations, we conclude that basing case definitions on precise medical observations, implementing initial comprehensive data collection, including environmental, social and behavioural information; and involving local informants could save precious time and hasten implementation of control measures.

Investigating reports of cancer clusters in Canada: a qualitative study of public health communication practices and investigation procedures

INTRODUCTION:

Public health officials provide an important public service responding to community concerns around cancer and often receive requests to investigate patterns of cancer incidence and communicate findings with citizens. In this study, we identified procedures Canadian public health officials followed when investigating reports of cancer clusters, and explored the challenges officials faced conducting risk communication with communities.

METHODS:

Thirteen interviews were administered by telephone with 15 officials across Canadian jurisdictions and analyzed using thematic analysis. A content analysis of procedural documents received from five provinces was also undertaken.

RESULTS:

A third of provinces/territories in this study did not use any consistent guidelines to investigate reports of cancer clusters, a third used their own guidelines and a third used guidelines from other countries. Each Canadian jurisdiction identified a different agency or individual responsible for investigating cluster inquiries. Officials in most interviews considered public education to be the primary objective of risk communication during an investigation. Officials in only 4 of 13 interviews cited an overall positive response from the public after investigating reports of a cancer cluster.

CONCLUSION:

Differences in practices used to investigate suspected cancer clusters by public health officials were revealed in this work. Establishing pan-Canadian cancer cluster guidelines could improve procedural consistency across jurisdictions and offer enhanced opportunities to compare cluster responses for evaluation. A reporting system to track reported clusters may improve information sharing between federal, provincial/territorial and local investigators. During formal investigations, face-to-face participatory communication approaches should be explored to improve citizen engagement and manage community concerns.

Uses of oral history and digital storytelling in public health research and practice

OBJECTIVES

Oral history (OH) and digital storytelling (DST) have been used in a range of ways in public health, including educating populations about health-protecting practices, advocating for improved clinical care and reflecting on public health efforts to combat infectious disease. Yet, these methods are rarely recognized for their potential to contribute to public health research and practice. The aim of this article is to assess how OH and DST have been used in the health fields and to provide examples of ways that these methods have contributed to work in several domains of public health.

STUDY DESIGN

Narrative review.

METHODS

We conducted a narrative review of articles gathered from PubMed using the search terms 'oral history' and 'digital storytelling', which resulted in 102 articles relevant to public health. We then conducted a thematic analysis to create a typology of article topics and to examine cross-cutting themes.

RESULTS

OH and DST have been used for both research and interventions in public health. Specifically, they have been used to 1) examine health risks and experiences; 2) engage and educate populations; 3) educate clinical professionals and organizations; and 4) inform public health practice.

CONCLUSIONS

Despite the time, resources, and training required to do OH and DST well, we argue that these methods have substantial potential for supplementing public health activities, allowing the field to glean additional lessons from its experiences, to educate its practitioners further, and to better learn from the experiences of communities affected by public health problems.

An investigation of cancer rates in the Argentia region, Newfoundland and Labrador: an ecological study

BACKGROUND

The Argentia region of Newfoundland and Labrador, Canada, was home to a US naval base during a 40-year period between the 1940s and the 1990s. Activities on the base resulted in contamination of the soil and groundwater in the region with chemicals such as heavy metals and dioxins, and residents have expressed concern about higher rates of cancer in their community. This study investigated the rate of cancer diagnosis that is disproportionately high in the Argentia region.

METHODS

Cases of cancer diagnosed between 1985 and 2011 were obtained for the Argentia region, two comparison communities, and the province of Newfoundland and Labrador. Crude and age-standardized incidence rates of cancer diagnosis were calculated and compared. The crude incidence rate was adjusted for differences in age demographics using census data, and age-standardized incidence rates were compared.

RESULTS

Although the Argentia region had a higher crude rate of cancer diagnosis, the age-standardized incidence rate did not differ significantly from the comparison communities or the provincial average. Argentia has an aging population, which may have influenced the perception of increased cancer diagnosis in the community.

CONCLUSIONS

We did not detect an increased burden of cancer in the Argentia region.